Solution composition for steel sheet surface treatment, zinc-based plated steel sheet surface-treated with same, and manufacturing method therefor

Abstract

Provided is a solution composition for steel sheet surface treatment, comprising 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 0.5 wt % to 2.0 wt % of a silane coupling agent; and 27.3 wt % to 64.2 wt % of water, a zinc-based plated steel sheet surface-treated with the same, and a manufacturing method therefor, the zinc-based plated steel sheet surface-treated with the solution composition for steel sheet surface treatment containing trivalent chromium may have an excellent effect on corrosion resistance, blackening resistance, fingerprint resistance, oil resistance, and alkali resistance.

The invention claimed is: 
     
       1. A solution composition for steel sheet surface treatment, comprising:
 30 wt % to 60 wt % of a trivalent chromium compound containing chromium phosphate (A) and chromium nitrate (B); 
 0.2 wt % to 0.4 wt % of a rust-inhibiting and corrosion-resisting agent; 
 0.1 wt % to 0.3 wt % of a molybdenum-based compound; 
 5 wt % to 10 wt % of a water-soluble cationic urethane resin; 
 0.5 wt % to 2.0 wt % of a silane coupling agent; and 
 27.3 wt % to 64.2 wt % of water. 
 
     
     
       2. The solution composition for steel sheet surface treatment according  claim 1 , wherein the chromium phosphate (A) and the chromium nitrate (B) satisfy a content ratio A/(A+B) of 0.3 to 0.6. 
     
     
       3. The solution composition for steel sheet surface treatment according  claim 1 , wherein the rust-inhibiting and corrosion-resisting agent is one or more selected from the group consisting of a fluorine-based rust inhibitor, a vanadium-based rust inhibitor, a cerium salt-based rust inhibitor, and a cobalt-based rust inhibitor. 
     
     
       4. The solution composition for steel sheet surface treatment according  claim 1 , wherein the molybdenum-based compound is one or more selected from the group consisting of molybdenum oxide, molybdenum sulfide, molybdenum acetate, molybdenum phosphate, molybdenum carbide, molybdenum chloride, molybdenum fluoride, and molybdenum nitride. 
     
     
       5. The solution composition for steel sheet surface treatment according  claim 1 , wherein the silane coupling agent is one or more selected from the group consisting of 2-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, N-2-(aminoethyl)-3-aminopropyl methyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2-(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-ureidopropyl trimethoxysilane, and 3-ureidopropyl trialkoxysilane.